I am doing my science fair project on how harmful algal blooms impact water systems. I was planning on growing algae, but I have not decided on a dependent variable yet. I was thinking of measuring the effect of algae on the growth of aquatic plants, but I have a limited time frame. I also thought about using water quality (such as oxygen levels or pH) as the dependent variable, but wanted to do something a little more complex. Do you have any suggestions or ideas? Thank you so much!

Algae blooms are a serious problem because of the damage they can do to marine or freshwater environments and the fact that some of them are very toxic to humans. Your project plans got me thinking about ways that we might reduce the bloom without any harmful side effects to other aquatic organisms. One of my favorite aquatic organisms is the water flea, Daphnia magna and they eat algae, so why not use them to devour an algal bloom.

If you are interested in testing Daphnia as a way to remediate an algal bloom please post again and we can help you with the details. Or maybe one of the other experts will have an idea about your original question as to what dependent variable to use in testing the effects of the algal bloom. Some kinds of algae can be toxic to humans as well as fish so be careful in handling them.